A driver requires performing drive operation while confirming a surrounding state of a vehicle to avoid collision with an obstacle around the vehicle or object approaching the vehicle from a distance in starting the vehicle parked in a parking section from the parking section. As a method of confirming a state of surroundings of an own vehicle, a driver directly confirms with eyes, and a system enlarging a field range simulatively is implemented by displaying an image on a monitor by a mirror or camera to supplement a dead area. Further, to assist driver's judge, not only the driver confirms with eyes, but also a system that detects and notifies obstacles or approaching vehicles around the own vehicle is also implemented.
In this way, to assist a visual field of a driver by a camera, a sensor such as a sonar or the like, it is required to switch a field direction or field range necessary to attract attention in accordance with a parking style such as a parallel parking or perpendicular parking. Therefore, various inventions have been proposed (for example, see Patent Literatures 1 and 2).